CalculationTime

Sunrise Star Map

A pre-dawn sky calculator aligned to true sunrise azimuth for the selected place and date, framed in the shared CalculationTime calculator and clock system.

Time Duration Calculator

Parameters

Sunrise star maps rely on date, location and true horizon geometry.

60 min before sunrise
Geolocation
Latitude51.5072°N
Longitude0.1276°W
Syncing celestial catalog...

Live math canvas

Your numbers, formula and explanation together

The star map calculates sunrise time, true sunrise azimuth and the pre-dawn sky projection for the selected place and date.

Formula applied

The exact method behind this answer

CalculationTime keeps the method visible so the number can be checked instead of blindly trusted.

Sunrise is solved near solar altitude -0.833 degrees; the star map uses local sidereal time to project visible stars above the horizon.
  1. Apply the methodSunrise is solved near solar altitude -0.833 degrees; the star map uses local sidereal time to project visible stars above the horizon.Sunrise azimuth and star fieldThe selected place and date determine the sunrise point and visible pre-dawn stars.

Your live breakdown

Current calculator context

This page keeps the active calculator, default worked example and method beside the tool so the answer is not separated from its arithmetic.

Calculator
Sunrise Star Map
Computed dawn sky
Sunrise azimuth and star field
Current method
Sunrise is solved near solar altitude -0.833 degrees; the star map uses local sidereal time to project visible stars above the horizon.

Resulting answer

Sunrise azimuth and star field

The selected place and date determine the sunrise point and visible pre-dawn stars.

Calculator
Sunrise Star Map
Computed dawn sky
Sunrise azimuth and star field
Current method
Sunrise is solved near solar altitude -0.833 degrees; the star map uses local sidereal time to project visible stars above the horizon.

Assumptions used

What this answer assumes

These boundaries keep the calculation honest and make clear when a specialist rule set is needed.

  • Sunrise uses a standard -0.833 degree altitude correction for refraction and solar semi-diameter.
  • The horizon is treated as a level mathematical horizon.
  • The star projection depends on latitude, longitude, date and local sidereal time.
  • Buildings, hills, elevation, haze and weather are not modelled.

Master’s Tip

How to use the result well

Master’s Tip: use the map as a planning guide, then check local horizon obstructions and weather before expecting the sky to match perfectly.

Printable record

What belongs in the saved calculation

For a selected city and date, the page finds the sunrise time, subtracts one hour for the pre-dawn view, then centres the map on the true sunrise azimuth.

Calculator
Sunrise Star Map
Computed dawn sky
Sunrise azimuth and star field
Current method
Sunrise is solved near solar altitude -0.833 degrees; the star map uses local sidereal time to project visible stars above the horizon.

Embeddable calculator

Embed this calculator

Copy a clean iframe version with the required CalculationTime attribution link built in.

Methodology & Accuracy

Calculation method and limits

The page combines a standard sunrise altitude correction, Julian-date solar position arithmetic and local sidereal time to draw a practical pre-dawn sky view.

Mathematical assumptions

Sunrise is anchored to -0.833 degrees solar altitude, combining standard atmospheric refraction and the solar semi-diameter used for upper-limb sunrise estimates.

Sky projection

The map evaluates local sidereal time, projects visible stars above the horizon, and centres the view on the calculated sunrise azimuth.

Horizon limitations

Results assume a level mathematical horizon. Hills, buildings, elevation, weather and magnetic declination can change field observations.